Winter storm Gemini is unrelenting this holiday season. The seventh named storm this season gripped Toronto with high gusts of wind, freezing rain and subzero temperatures, causing a power outage for more than 250,000 people.

Toronto Hydro said power may not be restored before Christmas Day, the Toronto Starreports.

“It truly is a catastrophic ice storm that we have had here, probably one of the worst we’ve ever had,” said Toronto Hydro CEO Anthony Haines.

Mayor Rob Ford said the city will call a state of emergency should conditions worsen. The severe weather has already caused flight cancellations and stalled transit systems.

“This is one of the worst storms in Toronto’s history,” Ford said.

Meanwhile, heavy snow and ice continue to hit parts of the Midwest and northern New England on Sunday, with seven deaths reported, while Philadelphia and New York City enjoyed warmer temperatures in the upper 60s.

Oklahoma, southwest and central Missouri and southeast Kansas are bracing for ice accumulations, while snow showers are expected in central and eastern Iowa, extending to northern and western Illinois, Wisconsin and northern Michigan, according to Weather.com. The heaviest snow will fall northwest of Chicago, but is likely to subside by Sunday afternoon.

Parts of the Northeast, including New York City and Philadelphia, are enjoying a surge of warm, wet air that has brought springtime temperatures in the upper 60s and lower 70s. Meanwhile, significant ice storms continue to hit upstate New York, New Hampshire, northern Vermont, as well as southern and central Maine.

An earlier version of this article misstated the name of Toronto’s mayor. He is Rob Ford, not Force.